Jay Ambler wrote: In 1990 Kendall Windham and his father Blackjack Mulligan were arrested by the US Secret Service in a joint investigation with the Florida Department of Law Enforcement (FDLE) for counterfeiting. The authorities found close to $500,000 in phony $20 bills. As a result of a plea agreement both father and son spent 24 months in a federal prison and were released in 1992.